Dispersal of rockets



1967 B. B. GOULD 3,318,241

DISPERSAL OF ROCKETS Original Filed June 21, 1961 Fly. 1

I INVENTOR. 1a

5527 5. 60040 Fl;- 5 BY ATTOZ/VEKS 3,318,241 DISPERSAL OF RUCKETS BertB. Gould, Berkeley, Calif., assignor, by mesne assignments, to MBAssociates, San Ramon, Calif. Continuation of application Ser. No.118,685, June 21, 1961. This application Feb. 4, 1965, Ser. No. 431,7784 Claims. (Cl. 102-7.2)

This invention relates to a method and apparatus for the aeriallaunching of a plurality of miniature rockets.

This application is a continuation of my copending application Ser. No.118,685, filed June 21, 1961, now abandoned, and entitled, Dispersal ofRockets.

Aerial launching of large rockets is accomplished singly, withorientation and guidance supplied by the launching platform (aircraft orfirst stage rockets) or the target. The miniature rockets to which thisinvention relates are too small to include guidance mechanisms and, tobe effective, are launched in such large numbers that individuallaunching platforms would be impracticable. Said miniature rockets areextremely small in size wherein the rocket has a diameter about 1.5 to 3millimeters. Such miniature rockets, aerially launched in a downwarddirection, are an effective weapon against dispersed troops in foxholesor trenches. It is, of course, desirable that excessive concentrationsof such miniature rockets be avoided directly below the launching point.

A suitable method for accomplishing these objectives has been devised,comprising three steps of dispersion, orientation and ignition.Dispersion is effected by the use of a slow explosive, by air blast, orby centrifugal force. A timed period of free fall will orient rockets ofproper design. Ignition effected by the ambient atmosphere ends the freefall and starts powered flight to the target.

In the drawings forming part of this application:

FIGURE 1 is a side view of a warhead of a shell or rocket opening topermit dispersion;

FIGURE 2 is a section through the warhead after the protectiveinsulation has been removed;

FIGURE 3 is an enlarged diagram of the essential elements in theorientation of a miniature rocket;

FIGURE 4 is an elevation view of the paths of free fall and poweredflights; and

FIGURE 5 is an enlarged section view of a miniature rocket showing themethod of ignition.

Turning now to a description of the drawings by reference characters,there is shown the body of a projectile 1, either shell or rocket, atthe instant of separation of segments 2, of forward insulating skin. Anexplosive charge 3 is used to accomplish separation. A series of trays4, inside the warhead, hold miniature rockets 6.

If the projectile 1 is rotating on its axis when the charge 3 isexploded, centrifugal force will disperse the miniature rockets 6 to allsides. Alternatively, or in addition thereto a second charge may beexploded in the central cavity 5 to propel the trays 4 and thereby theminiature rockets 6 to all sides. Also, a conical forward entrance 7 tothe cavity 5 may be employed to propel the trays 4 to all sides by airpressure generated from the downward motion of the projectile. The traysmay be connected to each other by lengths of cable (not shown) to insuremovement of the miniature rockets free of the trays 4 after lateralacceleration.

Once a miniature rocket 6, as shown in FIGURE 3, is in free flight, theinertial force resulting from its lateral velocity and the similar forcefrom the original downward velocity of the projectile 1, plus gravity,will act on the center of gravity 8A of the rocket as shown by thearrow. Air drag will act on the center of pressure 8B of the rocket asshown by the arrow attached to that point. Because the center of gravity8A is forward of the center pressure 8B, the rocket will rotate as shownby the curved arrows nited States Patent ice until it is oriented in thedirection of its motion through the air. To aid in the separation of thecenters of gravity and pressure, fins may be added to move the center ofpressure rearward, or the nose of the rocket may be weighted to move thecenter of gravity forward.

From the point of aerial dispersion 9, FIGURE 4 shows the theoreticaltrajectories 10, 11, 12 of miniature rockets expelled laterally withhigh, intermediate and low velocity respectively. After the ignitionpoint 13 these trajectories are powered and substantially straight.However, such trajectories are not desirable in that the pattern atground level 15 will not cover an area directly below the point ofdispersion 9, and since most of the miniature rockets will receivesubstantially identical lateral accelerations, said trajectories willtend to concentrate in a ring at ground level. On the opposite side ofthe centerline of FIGURE 4 are shown more realistic trajectories 14, inwhich allowance has been made for random variations in orientation andtime of free fall before ignition. Such variations effect even coverageof the ground level 15. It is therefore important to avoid excessiveorientation moments (FIGURE 3) that will bring all rockets to completealignment with their theoretical trajectories before powered flight.Variations in the time of free fall act to select a different slope onthe descending parabola and add to the randomness of the distribution.

In FIGURE 5, the enlarged section of a miniature rocket 6, shows themethod by which ignition may be accomplished. The fuse 16 extendsthrough the nozzle 17 and the central port of the propellant grain 18. Asmall piece of white phosphorus 19 is fastened into the nozzle exit incontact with the fuse 16 with a combustible cement 20 such asnitrocellulose. An inert, non-oxidizing atmosphere such as nitrogen,argon, or carbon dioxide is maintained around the rocket. Handling ofthe miniature rockets is thereafter accomplished in a similarnon-oxidizing atmosphere, including delivery over the target in thewarhead of a projectile. When the insulating skin is removed as shown inFIGURE 1, air reaches the pellet of white phosphorus and causes ignitionof the fuse. Since ignition of the propellant will not occur until thefuse has burned substantially through the propellant, the time of freefall may be altered by adjusting the burning speed of the fuse.

I claim:

1. The method of dispersal firing of clusters of miniature rocketstowards a target area comprising the steps of releasing a bombletcontaining a multiplicity of miniature tubular rockets containingpropellant for self-propulsion and having a center of gravity and acenter of pressure with the center of gravity between the center ofpressure and the forward end of the rocket and the center of pressurebetween the center of gravity and the aft end of the rocket, opening thebomblet while in flight above the surface of the earth, allowing therockets to fall in free flight free of the bomblet whereby the centersof gravity and the centers of pressure react to the surroundingatmosphere substantially to align the rockets with the direction offlight and to effect dispersal of the rockets, and igniting thepropellant while in the directed flight whereby the rockets becomeself-propelled towards the target area.

2. The method of dispersal firing of clusters of miniature rocketscomprising the steps of releasing a bomblet containing a multiplicity ofminiature tubular rockets containing propellant for self-propulsion andhaving their center of gravity and center of pressure arranged with thecenter of gravity between the center of pressure and the forward end ofthe rocket and the center of pressure between the center of gravity andthe aft end of the rocket, opening the bomblet in flight above thesurface of the earth to release the multiplicity of rockets, allowingthe rockets to fall in free flight for a distance short of the surfaceof the earth whereby the centers of gravity and the centers of pressureoperate to align the rockets with the direction of flight and to effectdispersal of the rockets, causing the propellant to ignite duringdirected free flight whereby the rockets are propelled in the directionof flight to the earth.

3. The method as claimed in claim 2 which includes the step of firing anexplosive within the bomblet for opening the bomblet and dispersing therockets originally housed therein.

4. A warhead for a projectile or rocket comprising in combination:

(a) a protective covering enclosing a holding structure;

(b) a plurality of miniature rockets within said cover- (c) saidcovering being hermetically sealed and having an inert gas filling;

(d) Said plurality of miniature rockets within said cover being held bysaid holding structure;

(e) each of said rockets having a fuse therein which References Cited bythe Examiner UNITED STATES PATENTS Dunajeif 10250 Rouse 1027.2 Gillon1026 Stanly 102-50 Loedding 10249 'Snelling 1026 Pigrnan 1027.2 Pigman1027.2

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL W. ENGLE, Examiner.

4. A WARHEAD FOR A PROJECTILE OR ROCKET COMPRISING IN COMBINATION: (A) APROTECTIVE COVERING ENCLOSING A HOLDING STRUCTURE; (B) A PLURALITY OFMINIATURE ROCKETS WITHIN SAID COVERING; (C) SAID COVERING BEINGHERMETICALLY SEALED AND HAVING AN INERT GAS FILLING; (D) SAID PLURALITYOF MINIATURE ROCKETS WITHIN SAID COVER BEING HELD BY SAID HOLDINGSTRUCTURE; (E) EACH OF SAID ROCKETS HAVING A FUSE THEREIN WHICH ISSELF-IGNITING IN THE PRESENCE OF OXYGEN BUT WHICH WILL NOT IGNITE IN THEPRESENCE OF THE INERT GAS FILLING; (F) MEANS FOR REMOVING SAIDPROTECTIVE COVERING; (G) SAID ROCKETS PARTIALLY DISPERSING WHEN SAIDPROTECTIVE COVERING IS REMOVED AND SAID IGNITION MEANS CAUSING FURTHERDISPERSAL OF THE ROCKETS UPON CONTACT OF THE SELF-IGNITING FUSES OF THEROCKETS WITH AIR.